Fluid connections in flow lines are commonly used in the transportation and distribution of products, such as propane and anhydrous ammonia. These fluids, when vented to atmosphere, are regarded as harmful to the environment. It is thus desirable to minimize the amount of liquid that is trapped in a connection upon closure of the upstream and downstream valves. U.S. Pat. Nos. 6,237,633 and 6,155,295 discloses an improved flow connect system that minimized the release of product during a disconnect operation. The system includes an inlet ball valve member with it's outlet port configured as an industry standard male acme connection and a downstream check valve with it's inlet port configured as an industry standard female acme “hammer union” type connection. While this system provided for minimal flow restriction and minimal release of trapped liquid upon disconnect, it failed to address the industry standard of a male acme connection at the inlet port of the downstream valve.
With the configuration of '663 patent, the user would have to convert a fleet of vehicles using the patented system because once the upstream valve was converted to the male acme configuration, it would no longer connect to the normally configured male acme connection in the vehicle fleet. Other patents disclosing ball valve disconnect systems include U.S. Pat. Nos. 4,023,773, 4,124,036, 5,255,121 and 6,056,012.
In various applications, it is thus desirable to use a ball valve for the upstream valve for flow considerations, but to have its outlet port configured with a female acme connection. In this situation, the filling station could still connect to and fill a truck outfitted with the industry standard male acme connection, although the released product at disconnect would be greater than if the vehicle were outfitted with a check valve that minimized the product release. With this setup, the fleet of transport vehicles can be converted gradually to reduced release downstream check valves while allowing the filling operation to connect to all the vehicles in the fleet.
The disadvantages of the prior art are overcome by the present invention, and an improved ball valve for threaded interconnection to a separable component having a male thread is hereinafter disclosed.